My research
examines the interelationships between plant ecology and population
genetics, and how these in turn influence the evolution of plant
reproduction. In this regard I study things like how differences
in fruit and seed morphology affect dispersal and gene flow, how
pollinator behaviors differ in relation to flower and inflorescence
size or density, and how this in turn affects plant outcrossing rates,
etc. Most projects involve both a field and laboratory
component. Much of the field work currently takes place at The Rocky Mountain Biological Laboratory,
near Crested Butte, Colorado. In the lab I use a number of
genetic markers (allozymes, nuclear microsatellites, AFLPs, and
chloroplast DNA RFLPs and sequences) to examine the genetic
consequences of variation in reproductive ecology and infer the
ecological and evolutionary history of different plant populations and
species. I also collaborate with other researchers
and students to apply molecular genetic techniques to answer ecological
and
evolutionary questions about a variety of other organisms, both plants
and
animals. Several of my main projects are outlined below:

Hermaphrodite Flower Female Flower

1. Evolution of Gynodioecy in Geranium richardsonii.
Gynodioecy is the production of separate hermaphroditic and female
individuals in a population. Femaleness, or loss of male
reproductive function, is caused by one or more male-sterility genes
typically located in the mitochondrial genome. Male sterility
should be at a fitness disadvantage unless
it is compensated for by increased female reproductive success relative
to hermaphrodites. My research with Geranium richardsonii examines
several hypotheses for the selective maintenance of male sterility
including resource allocation to flowers and seeds (female flowers are
smaller, but produce more seeds than hermaphrodites), and
self-fertilization and inbreeding depression (females cannot self,
while hermaphrodites do so at rates > 50% and appear to suffer
substantial inbreeding depression at different
stages of the life cycle). Additionally, relative fitness of the
genders
is density- and frequency-dependent, with females suffering pollen
limitation when at high frequency. I am investigating this
phenomenon of density- and frequency-dependent fitness at a number of
different spatial scales
(local neighborhood, population, metapopulation). I am also
investigating
the mode of inheritance of male-sterility through a multi-generation
crossing experiment. Finally, I am developing chloroplast DNA
markers to investigate gene flow through seeds, and its relation to
dispersal of male-sterility
genes.

2. Reproductive Ecology and Genetics of Delphinium
species. The genus Delphinium (Ranunculaceae), or
Larkspurs is globally distributed and over 60 species occur in North
America. Larkspurs are pollinated predominantly by
bumblebees and hummingbirds. I have been investigating the
reproductive
biology, population genetics, and mating systems of two common species
of
the Western US, Delphinium nuttallianum, and D. barbeyi.
Delphinium nuttallianum blooms shortly after snowmelt and has
only 5-10 flowers
on a single stalk. This species is highly outcrossed and hence
shows
little spatial genetic structure. Delphinium barbeyi
blooms
later, and has hundreds of flowers on multiple stalks. Self
pollination
by geitonogamy (between flowers on the same plant) reduces outcrossing
to
about 50%, and populations are highly structured in space at a number
of
scales. With students and collaborators I am currently
investigating
the effect of variation in inflorescence size and plant density
on
the mating systems of these and other Delphinium species.

3. Alternative Male Mating Strategies and Multiple
Paternity in Burying Beetles. In
collaboration withDr. Rosemary Smith (ISU), I
have been investigating the paternity of burying beetle (Nicrophorus
sp.) broods using microsatellite markers. Burying beetles
have biparental care of their brood, which is raised on a buried small
mammal carcass as a resource. Larger males are at a reproductive
advantage in securing a carcass and defending it against intruding
males. Smaller males
may adopt a "female mimic" strategy in which they are able to sneak
copulations and thus gain at least partial paternity of broods they do
not help to
raise. Additionally, females may be able to store sperm and thus
not all offspring within the brood may by the progeny of the resident
male.
Using highly variable microsatellite DNA markers we are assessing the
prevalence
of multiple paternity in the field and the success of alternative male
strategies in laboratory-raised broods.

I've taught
several courses since coming to ISU. There are links to each
course web site for those I am currently teaching. I am also
involved in teaching and mentoring research students at The Rocky Mountain Biological Laboratory each
summer.

Darwin Seminar -
BIOL 499/599 - A seminar for graduate students and advanced
undergraduates to read and discuss Darwin's influential work.
Occasional offering (On the Origin of Species - Spring 2006, Descent of
Man and Selection in Relation to Sex - Fall 2008)

Ecology and
Evolution of Flowers Seminar - BIOL 499/599 - Using Harder and
Barrett's (2006) volume "Ecology and Evolution of Flowers" and the
primary literature to explore recent theoretical and empirical advances
in the field (Fall 2008)

INFORMATION FOR PROSPECTIVE STUDENTS:
Students interested in research in molecular ecology, plant
reproductive ecology, and plant population genetics, evolution or
systematics are welcome to contact me about the graduate program and
potential research projects at ISU and RMBL. I have been actively
involved in training undergraduate and graduate students in research
and teaching. There are many opportunities for research at both
the undergraduate and graduate levels in the Department of Biological
Sciences at Idaho State University. The department offers
graduate training in the Master
of Science, Ph.D. and Doctor of Arts (for students emphasizing college
teaching) programs. There is funding available for both undergraduate
and graduate
research through the University Undergraduate and Graduate Research
Committees,
Teaching Assistanceships in the Department of Biological Sciences and
the NSF funded GK-12 program.
Graduate
students are encouraged to develop an independent research project and
apply
for external funding through State and Federal agencies, including the
National
Science Foundation.

GRADUATE
STUDENTS: Since moving to ISU I've worked with a
number of M.S. and Ph.D. students as research advisor,
graduate committee member, and mentor for Doctor of Arts (D.A.)
teaching internships. Some of the students
and projects are listed below:

Downloadable .pdf
versions of some of these papers are available by clicking on the links
below. If you need a
copy of Acrobat Reader for your computer it can be downloaded for free
at the Adobe
Acrobat site.